If quality of life (QOL) data are to be useful in clinical settings, they must be accurate, precise, responsive to meaningful change, and interpretable. Making a step in that direction, R01 CA60068 ( Quality of life evaluation in oncology ) was a three-year project with the primary aim of developing a common QOL metric ( Q-score ) and a common language for QOL data. Under this grant we have developed standardized scores for five commonly used QOL questionnaires: The Cancer Rehabilitation Evaluation System, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core, the Functional Assessment of Cancer Therapy-General, the Medical Outcomes Study 36-Item Short-Form Health Survey and the Quality of Life Index. The primary aim of the current project has been accomplished, leading to the proposed logical extension of work which will utilize Rasch measurement and confirmatory factor analysis (CFA) to: 1) Construct and extend an item bank for quality of life (QOL) outcomes; and 2) Develop and pilot QOL computerized adaptive testing (CAT) in clinical settings with cancer, HIV/AIDS and stroke patients. These two specific aims will be accomplished through four projects which will span five years: Project 1: Construct an initial item bank (database) comprised of previously calibrated and tested questions from the RAND-36 (aka SF-36), EORTC QLQ-C30, CARES-SF, FACT-G, and QLI. Preliminary item difficulties for the complete set of questions (Overall QOL) and for subsets of questions which define and measure physical well-being (PWB) and mental well-being (MWB) will then be established; Project 2: Acquire items into the bank which fill current item difficulty gaps in PWB and MWB, and which allow for possible building of a third summary QOL dimensions, social well-being (SWB), and overall QOL (n=195). The acquisition task will be done in a way which allows for future selection of items which are shown to be sensitive to relevant clinical and QOL change; Project 3: Test the equivalence of computer-based testing (CBT) versus paper-and-pencil (P and P) assessment across three diagnostic patient groups: Cancer, HIV/AIDS and stroke (n=600); and Project 4: Develop a CAT platform for QOL assessment (n=45), then pilot in clinical settings (n=200), test the equivalence of measures obtained via CAT versus conventional assessment, and explore sensitivity to clinical change.